This is literally something that DEFINES DoTA and League, it's not a benefit one has over the other.

LoL intentionally has core items for specific roles and Champions for specific purposes, while DoTA has item builds for specific purposes and Champions for specific roles.

If you want it put differently,, LoL has Attack Damage, Ability Power, and Tank Stats, while DoTA has the three specific stats from Warcraft 3.

This is just a choice. So far as I know, Riot's designers frown on items so powerful they anchor the game (see: Morello's hate for DFG). They want champions to be selected as the anchors to your team ability, not items.

I couldn't find a DotA item that gave a small amount of flat mana so I could use an ability on a bear summon which doesn't have mana. I was sad.

...i'm not a dota fan (or hater) but i took one look at that awesome map and got jealous

Dota also scales in an entirely different way from lol.

The changes to Black cleaver, Tiamat, and the new QQS upgrade are all example of Riot indirectly buffing less played character classes.

Let's face it, Mercury Scimitar is the Lol version of BKB. It isnt as op, but then, nothing in LoL is as OP as it's nearest equivilant in DotA. ("If everything is OP, nothing is.") It's strong MR plus a clense on a stick aimed for melee AD champs, which includes melee carries, a class rendered unviable because of chain CC and AP nukes.

I think the S3 patch is moving in the right direction for the game as a whole. (i.e making the game a more diversified "balenced" game). In my opinion, an item should help channel your role more precisely for that specific match you've been qued in. I can't think of an item so far that I've seen be completely ignored in this patch. (Zephyr's time will come!)
Item Diversity is a cool thing to discuss, but when you talk about DOTA you open up a whole new can of issues with that game. Sure they might have "good, unique item choices" but mainly when you look at the list of 25-35 heroes (if that) out of their tier lists, most of the players build roughly the same items every game. no matter what. at all. NO MATTER WHO THEY ARE PLAYING><

TL;DR Item Diversity is cool. Having Diverse PLAYSTYLES is far better.

I thought this thread was going to be about voice comm.